Tom Brady's contract extension with the New England Patriots provides a window into one option for the Minnesota Vikings to address Jared Allen's big cap number for 2013.

Brady was due $9.75 million in base salary each of the last two seasons of his deal. But his cap number was scheduled to be $21.8 million, thanks to $5 million roster bonus payments each year, $250,000 workout bonuses and leftover bonus proration from two previous renegotiations.

So, the Patriots wrapped all that money -- $30 million total, between the salaries and bonuses -- and converted it into a signing bonus they prorated through 2017 by tacking on three years to Brady's existing deal in a deal finalized on Monday.

The result was Brady getting a modest raise in the form of base salaries of $1 million in 2013 and $2 million in 2014 on top of the $30 million signing bonus, which he'll be paid over the next two years, and the Patriots getting $15 million in cap relief over the next two seasons.

Brady's 2013 cap number was the highest in the NFL before the renegotiation. Allen's isn't far off at $17,063,956 -- ninth-highest in the league and third among non-quarterbacks, behind only Detroit's Ndamukong Suh ($18,172,500) and Kansas City's Tyson Jackson ($17.47 million).

The Vikings have planned for the possibility of having to carry Allen's number for some time, since they never want to be caught in a bind. Without making any cuts or restructures, they remained just above the middle of the NFL in cap space as of Wednesday afternoon.

But negotiating a short-term extension that mirrors Brady's could give the Vikings significantly more cap flexibility if they choose to be active in free agency this year and provide Allen additional security in what otherwise would be the final year of his $73 million megadeal.

Allen is due $14,280,612 in base salary for 2013. For the sake of clarity, round that number down to $14 million and assume the Vikings convert that to a signing bonus on a three-year extension through 2016.

If Allen takes a $1 million base salary for 2013 -- i.e. a $1 million raise -- his cap number would plummet to a little more than $8 million because the signing bonus would be prorated over four years. (He also has $2,583,344 in remaining bonus proration from his expiring deal.)

Just like that, the Vikings would have another $9 million in cap space available in 2013.

It's not the pay-as-you-go model Rob Brzezinski, the Vikings' vice president of football operations, usually adheres to. But the long-term risk is relatively minimal, as it is with the Brady deal.

The new years on Brady's deal includes base salaries of $7 million in 2015, $8 million in 2016, $9 million in 2017 -- all guaranteed for injury only at the time of the signing. His cap number never rises above $15 million, and he's under contract through age 40.

Allen could take base salaries averaging around $8 million over the last three years of the contract and technically still rank among the 10 highest-paid defensive ends in the league.

The Vikings, in turn, could guarantee his base salaries for 2013 and '14 -- increasing the total guarantee to around $23 million when factoring in money from the old deal -- and only be on the hook for $7 million in dead money if they decide to cut him two years from now.

Now, there are two key questions here. Does Allen want to spend what could be the last productive years of his career in Minnesota, bypassing a chance to hit the open market one more time next March at age 31? And are the Vikings worried his play last season while battling a torn labrum in one of his shoulders that required surgery is a sign he's entering decline?

Allen is one year removed from a 22-sack season and hit double-digits in sacks for a sixth consecutive season in 2012. He's not an ascending player at this stage, but he remains productive in a defensive scheme that requires the front four to generate most of the pressure.

If he's offered a straight pay cut, Allen probably would call the Vikings' bluff, knowing that releasing him would be a massive PR hit and leave them with only two viable ends, Brian Robison and Everson Griffen, who both could become free agents next March as well.

Unless the Vikings believe Allen is nearing the end, the short-term extension makes sense from the team's perspective. And considering Allen actually would get a modest raise out of the deal in 2013, it's a good bet he'd listen -- unless he's hellbent on finishing his career someplace else.